东营凹陷下第三系地层异常高压体系及其石油地质意义

地层流体压力异常是含油气盆地存在的一个普遍现象。选用丰富的声波测井资料，根据等效深度法首次计算了东营凹陷下第三系地层异常压力和剩余压力值，分析了异常高压体系的发育特征及其对油气的控制作用。研究表明：高压体系的发育与欠压实、蒙脱石向伊利石转化以及油气的生成有关。异常高压是油气运移、聚集的主要动力，异常高压体系产生的流体压裂、幕式排烃作用对油气的运移聚集十分有利。油气主要分布在高压体系中的相对低压区。东营凹陷中央隆起带的塑性拱张构造是异常高压体系的泄压区，也是油气聚集的最有利区，其较深层位（Ｅｓ３中下─Ｅｓ４上）是今后油气勘探的有利目标。

Anomalous overpressure system of early Tertiary in Dongying depression and its petroleum geology significance.

Abnormal formation fluid pressure often exists in oil-gas bearing basin. With sonic log data and by means of equivalent depth method, the abnormal formation pressure and the residual pressure value of early Tertiary in Dongying depression are firstly calculated and studied in this paper. It indicates that development of overpressure system is related to undercompaction, smectite transferring into illite and petroleum generation. Overpressure system is the main driving force for hydrocarbon migration and accumulation. Hydrofracturing and episodic expulsion of hydrocarbon resulted from overpressure system are favorable for petroleum migration and accumulation. Petroleum is mostly distributed in the relative low-pressure area of the overpressure system. The plastic arch extension structure of central uplift area in Dongying depression is both the pressure release area of overpressure system and the very favorable area for oil and gas accumulation, in which the deeper formation (Mid-Lower Es3- Upper Es4) is the favourable target of oil and gas exploration in the future.